The typical aircraft wing assembly design includes leading and trailing edges with aerodynamic lifting surfaces disposed therebetween and at least one control surface device integrated into the trailing edge. Flaps and ailerons are common examples of such control surface devices. Flaps disposed opposing wings are designed to increase wing lift by operating in unison for increasing wing camber. By comparison, ailerons are designed for roll control and are oppositely pivoted on opposing wings to increase lift on one wing while reducing lift on the opposing wing to induce a rolling moment. Similarly, elevator sections are disposed about the horizontal tail and are pivoted for lift and pitch control. Other control surface devices include leading edge flaps, elevons, trim tabs, tail fins and rudders.
These conventional control surface devices are actuated by the application of torque about an axis which is parallel to the trailing edge of the device. As such, the torque or power requirement of such devices is directly proportional to impinging air loads as the control surface is rotated into an oncoming airflow. Thus, the greater the desired control surface deflection, the greater the torque required to cause and maintain such deflection.
In addition, these conventional control surface devices are generally rigid structures which maintain their shape while being deflected or rotated about an axis which is generally parallel to the wing trailing edge. As such, gaps or abrupt contour changes occur at the lateral hinge line area of these conventional control surface devices. This gap tends to increase aerodynamic drag thereat, and therefore decreases the efficiency of the control surface device. Additionally, as the control surface devices are rotated, cordwise gaps are formed between the edges of the hinged control surface devices and the adjacent fixed portions of wing assembly.
As such, based upon the foregoing, there exists a need in the art for an improved control surface apparatus.